Drill press



yMarch 19, 1935. C LANDRMN 1,994,772

DRILL PRESS Filed Sept. 19, 1933 INVENTOR Camilo Landfill/u 35 BY ATTORN EY Patented Mar. 19, 1935 4palmi PRESS` camino Lanariani, Bronxviue, N. y.

l'Aqprlication September 1 Y `3 lClaims.

This'invention relates to a rotary ldrive,yparticu larly of the type adapted for use in a sensitive drill pressfone iof the main objects of this invention being to permit the safe transmission of i a rotary driving motion to a tool of small and delicate construction. v l

d In the drilling of veryrne holes, the delicate drills employed for the purpose arey easily sub- (ject to breakage,-a condition'which is due to the fact that the drill, during its progress through the material being drilledjencounters portions of increased density or toughness, and inasmuch as the drill is generally actuated, by positive driving means, the relatively constant driving force lmay be suliiciently great to cause abreakageof the tool'gupon encounteringjsuch increased resistance.l To overcome this danger, l2 4have conceived this invention wher eby the driving means I employ is.

non-positive and of `what might be consideredl a frictional nature, and yet capable of transmitting the necessary driving forca-the arrangement being such thatwvhen thejdrill encounters any such increased resistance, there will be a slippage between the driving shaft andthe tool-carrying member, so that the resultant vspeed ofthe drilll will be automatically 'and adjustably decreased to prevent any unduegstrainuuponlthe drill at such point. Using a drill employing my invention', I'have been able to drill `holestwenty-live"ten thousandths (251105300) of an inch in diameter,V thereby making thisV device particularly applicable tothe processes of drawing celanese andlrayonl threads, for atomizing devices, andfor the-man` ufacture of delicate instruments suchas watches,

etc." i

In many industries whereit is necessary vto `drill very line holes, it has generally been the practice of fixingv the position of theseholes with punch marks-a method whichhas frequentlyv proven unsatisfactory the punching purpose.` Usin due to the fact that the point of tool was often tooblunt for the g my invention, however, small holesvcan readily `be drilled ,to' serve aspiloting for larger holes without the usedof punchingtools.

Other objects, features and advantageslwill appear, from the drawing and inafter given.

Referring to the description herethe drawing,

`Figure 1 is .an elevation ofv a: drillpress ern-'-v ploying my invention. y

Figure 2 is an enlarged fragmentary section taken along line 2 2 of Figure'l, showing a preferred form of ating the drill.

the transmission mechanism actu- 9, 193s, serial No. y690,053

(o1. 1re-5) Figure 3 is a sectional plan of Figure 2 taken along line 3 3, and i Figure 4 is a fragmentary section of a modifled formofthe transmission mechanism constituting my invention as used with a drill.

In the drawing, the motor 5 is connected to a variable speed drive comprising the driving wheel 6 in frictional engagementV with and at right angles tothe disk '7, the shaft 8 of theinotor being attached to the shaft of the wheel 6 by the slidable coupling 9. Pivotally attached to the coupling isthe lever 10 which ispivotally mounted-at l1`.- The link 12 ispivotally attached to the levers 10 and 13 intermediate the ends thereof, the free end of lever 13 containing the slot 14 therein which is in slidable and rotatable engagement with pin l5l attached to the end of the shank of the adjusting bolt 16, the latter being in threaded engagement with .the hollow internally threaded boss 17 'attached to the lug 18 20 o-f the casing 19 of the drill press. vThe adjusting bolt 16 is provided with the head or knob 20, adapted for manual manipulation, the hub 21 thereof being in engagement with the lug 18.

'Attached to the disk '7 is the shaft vor spindle 22 25 extending through the lug 23l of the casing 19 and supported by the bearing 24 which is attached to the'brack'et 25' mounted upon the post 26 of the ydrill press.

The bottom or free e y rotatably and slidably positioned by a runningv twithin the axial hole 2'7` of the cylindrical chuck-carrying member 23. `In the preferred form of mydevce, the axialhole does not extend through Ythe entire length of member 28, as appearsk from Figure 2. A channel 29 extendsfrom thebottom of said axial hole 27 through the stud 30, which is preferably integral with the memberv 28.l Iii-:threaded engagement with said stud is the chuck 3l which contains the chuck wedgesV 32 thereinv for detachably holding the drill 33 in its operative position. Attached to the bracket is the hollow guiding-V member 34v through which extends the rod 35 in slidable and rotatable engagement with the wallsof the'hole in said guide. Thehandle 36 is affixed to the said rod 35 the upper portionv of which contains the bifurcated bracket 37, the two arms of which (only one vbeing shown) support therebetween the roller 38. Pivotally attached to the guide member 344 is the lever 39 intermediate the ends of which is the arcuate arm 40 `containing the detent 41. The curvature of the arm 40 and its relationship to the lever 39 is such that the distance between the pivotal point nd oi"V the spindle 22 is 30' n 42 and the arm 40 increases for points farther removed from the lever 39; in other words, the distance between pivotal point 42 and detent 41 is greater than that from the point 42 to the juncture of arm 40 and lever 39, so that upon a moving of the lever 39 in the direction of the arrow, the arm 40 in rotatable engagement with the roller 38 will cause an upward movement of the bracket 3'7 and the rod 35,-the detent 41 representing the position of highest liftv of rod 35. The helical spring 43 'on the underside of the guide 34 and which is mounted over the lower portionvof rod 35 normally exerts a downward pull upon the rod, so that the roller 38 is always in yieldable engagement with the arm 40.

The lower extremity of rod 35 is attached to the chuck-supporting member 44, the horizontal arm of which contains a recess 45, near the chuck extremity thereof, adapted to accommodate the drill 33 when the arm is in its operative or chucksupporting position. The table 46, for supporting the material to be drilledis movable in a vertical direction by manipulationof the wheel 47.

In operating this device as applied to the drill press shown, the spindle speed 22 is adjusted by manipulating the knob 20 ofthe adjusting bolt 16. By turning this knob, the bolt 16 will move in a horizontal direction and, through the linkage shown and described, will cause the wheel 6 to move in a horizontal direction, the position of this wheel with respect to the disk '7 determining the velocity of the spindle. Before the drilling operation is commenced, the lever 39 is swung to the right in the direction of the arrow until the detent 41 is in engagement with the roller 38, the arm 44 underlying and supporting the chuck in its raised and inoperative position. InA

this position, the spindle 22 actuated by the motor 5, is in rotation.

After the work to be drilled is properly positioned on table 46, thelever 39 is moved slowly towards the left, thereby gradually lowering the rod 35 and the arm 44. Inasmuch as thechuck and chuck-carrying member 28 are supported only by arm 44, a lowering of said last mentioned arm will cause vmember 28Y andthe chuck to move downwardly under gravitational infin-- ence, the member 28 slidably moving along the spindle 22. When the point of the drill 33 contacts with the work, the handle 36 is swung towards the machine, thereby removing the arm 44 from its chuck-supporting position, so that the drill 33 supports the member 28 and the associated parts and is able to perform its drillingy operation.`-

It will be noted that the chuck-carrying member 28 contains an annular ridge 48 upon which ismounted the hollow cylindrical weight 49. For different siresA of drills, different weights are used, this weight serving the-purpose of supplying suflicient pressure to effect the required drilling operation.. Although in this preferred form a weight is shown, it is within the contemplation of my invention to use. any other means, such as a spring in operative engagement with the chuck-carrying member 28, to supply the necessary drilling pressure.` y

With the construction disclosed and hereinbefore described, it has" been foundthat the rotary motion of the spindle 22 is transmitted to the chuck-carrying member 28 to cause the operative rotation of the drill 33. My contention is that the vfrictional driving effect is greater than the resistance offered by the material to the-drill, thereby. enabling the drill actuated by the fric- 1,994,77a l y tional drive to cut through the material.` Should.

the drill 33, during its progress through the material being drilled, encounter a portion of increased density or toughnessthat is, should the drill meet with a resistance greater than the force of the frictional drive, there will be a slipf page between the member 28 and the spindle 22,

resulting in an automatically adjusted decrease y in the speed of the drill. In this manner, although slower progress Ais being made through the material at the point of increased resistance, no undue strain will be induced within the drill as would be the case with a positive drive of fixedv and unvariable speed.

I have found that very satisfactory results can be obtained .by coating the endof spindle 22 with a film of oil. In this case not onlyisthe life ofthe transmission mechanismincreased due to the natural effects of lubrication, but-suiilcient driving force is transmitted tothe chuckcarryingk member 28 to effect eicient'drilling operation. It-is my belief that this phenomenonv is produced by the uid drag resulting from the hydrostatic pressure induced within the lm'of..

oil. l

vWhen the spindle is so lubricated, no air ican pass between the klateral surface of Athe spindle and thecontiguous portion of the wall of the axial hole. When the chuck-carrying member. 28

is lowered into its operativeposition, the space in.'

the axial hole 27 beneath the. spindle `22r is yfilled with air; and when the said member 28 is raised,

upon the completion of the drilling operationthe` air in said space willtend to be compressed, 'but due to the presence ofthe channel 29 and the space 50 adjacent the chuck wedges, the air will beforced out therethroughfthereby permitting an .easy raising and loweringof'the said member 28.

Figure 4 represents ar modification of my invention, illustrating the use cfa rubber chuck 51 supporting the drill 52, thecapV 53, enclosing and supporting the rubberchuck 51, being in threaded engagement with the. stud 54 Vof/the chuck-carrying -member 55. A' channel 56,vr positioned underneath the. weightl, communicates, y between the lower portion of the vaxial ho1e`58 and the atmosphere, there being no other' holeanalagous'to 29l of Figure ,2. The-member55 is 1 fitted over the spindle 22 by a running t, similarV to that of the structuredisclosed'in Figure 2. The

transmission mechanism constructed in accordance with Figure A4 has similarly proven'efiectiv'e,

dle, and then out into the atmosphere through the channel 56.` The constantly moving fllm of air between the spindle and the wall of the axial hole results in sumcient fluid drag to cause a rotation of the chuck-carrying member and the operative n movement'of the drill.

It is of course understood that my invention consists of the mechanical combination of parts and the cooperablerelation of the elements as hereinbefore described, my beliefs as to the theory of the action as 'hereinbefore set' forth' being only explanatory and not being any part'of nor aifecting the invention proper.

Although Athis invention has been illustrated and described as applied to a drill press, vit is within my contemplation thatthis device, particularly the transmission mechanism, can be equally applied to other tools or apparatus for the transmission of rotary motion and particularly where it is necessary to adjustably decrease theY speed of the tool in accordance with variable resistances oiered the tool; and it is likewise understood that other forms and modifications of my invention may be employed within the scope of the appended claims.

What I claim is:

1. In a drill press, a vertical spindle, means to rotatably actuate the spindle, a cylindrical chuckcarrying member adapted to be driven by said spindle, said member having therein a vertical axial hole within which an end portion of the spindle is slidably and rotatably positioned, an annular ridge about the member, a cylindrical weight removably mounted over said member and supported by said ridge said weight being adapted to slidably actuate the member downwardly along the spindle, a chuck attached to the said member, a drill secured to said chuck, a swingably mounted and vertically movable arm underlying and supporting the chuck and the superposed parts, manually operated means associated with said arm for imparting vertical movement to the i arm and the parts supported thereby, and for swinging the arm out of engagement with the chuck.

2. In a drill press, a transmission mechanism comprising a spindle, means to rotatably actuate the spindle, a chuck-carrying member adapted to be driven by said spindle, said memberV having therein an axial hole within which an end portion of the spindle is slidably and rotatably positioned, an air film between the lateral surface of said spindle and the adjacent wall portion of said hole, an air channel within said member and below said spindle and communicating between said air film and the atmosphere, pressure-exerting means in operative engagement with said member to actuate it slidably along said spindle and longitudinally in the direction of the work to be drilled; a stud at the bottom of said member; a chuck of yieldable material at the lower extremity of said stud; a cap supporting and enclosing said chuck and in threaded engagement with said stud; and a drill extending 'into and secured to said chuck and extending outwardly through said cap.

3. In a drill press, a vertical spindle, means to rotatably actuate the spindle, a cylindrical chuckcarrying member adapted to be driven by said spindle, said member havingtherein a vertical axial holeV within which an `end portion of ythe spindle is slidably and rotatably positioned, an annular ridge about the member, a cylindrical weight removably mounted over said member and supported by said ridge, said weight being adapted to slidably actuate the member downwardly along the spindle, a chuck attached to the said member, a drill secured to said chuck, a horizontally disposed arm underlying and supporting the chuck and the superimposed parts, a vertical rod suitably affixed to said arm, means for slidably and rotatably supporting said rod, a pivotally mounted lever, an arcuate arm joined to said lever intermediate the endsl thereof, said latter arm containing a detent which is farther from the pivotal point of the lever than the juncture of said arcuate arm and lever, a roller aflixed to said rod, means for yieldably holding said roller in operative engagement with said arcuate arm and the said detent, a handle for operatively actuating said lever to cause said arcuate arm to vertically move said roller and the attached rod, and a handle for rotatably moving said rod. f

CAMILLO LANDRIANI. 

